Preparation method and application of antimony-doped graphite-phase carbon nitride composite material
By preparing antimony-doped graphitic carbon nitride composite materials, the capacity and stability issues of lithium/sodium-ion battery anode materials were solved, achieving performance improvement of lithium/sodium-ion batteries with high conductivity and high reversible capacity.
Patent Information
- Application Number
- CN202411891852.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2044-12-20
AI Technical Summary
Existing lithium-ion battery anode materials, such as graphite, have limited capacity; sodium-ion battery anode materials, such as hard carbon, have insufficient rate performance and cycle stability; and antimony-based anode materials suffer from severe volume expansion during cycling, leading to performance degradation.
Antimony-doped graphitic carbon nitride composite material was prepared by using g-C3N4 as the precursor carbon source and Sb2O3 as the dopant element. Hot tartaric acid solution was used as a solvent and binder. After mixing, the mixture was carbonized in an inert gas environment.
The prepared composite material has good conductivity and high reversible capacity, solves the problems of antimony agglomeration and volume expansion, and improves the cycle stability and rate performance of lithium/sodium ion batteries.
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Figure CN119750509B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of lithium / sodium ion battery preparation, and relates to a preparation method and application of an antimony-doped graphite-phase carbon nitride composite material. BACKGROUND
[0002] Secondary batteries have been widely used in energy storage technology and power systems. At present, most secondary batteries are lithium ion batteries based on lithium ion migration. However, the growing social demand puts forward higher requirements for the performance of lithium ion batteries, hoping that the lithium ion batteries have larger capacity, longer cycle life and faster charge-discharge speed. Through in-depth research, the electrical properties of the positive electrode material of the lithium ion battery have been significantly improved. However, the negative electrode also has a great influence on the overall performance of the battery. At present, the commonly used negative electrode material of the lithium ion battery is graphite, which has high theoretical specific capacity and has been difficult to meet the market demand of the positive electrode material. Therefore, developing a negative electrode material with high capacity, long cycle performance and high rate is an important direction for further improving the performance of lithium ion batteries.
[0003] As a homologous element of lithium, the proven reserves of sodium element are much higher than those of lithium, and the global distribution of sodium resources is relatively uniform. At present, the research direction is shifting to the development and design of sodium ion batteries. Graphite is the main and most commercialized negative electrode material for lithium ion batteries, but due to the weak interaction between sodium ions and graphite layers, sodium ions are difficult to insert into the graphite layers. At present, hard carbon is the main negative electrode material for sodium ion batteries, but its rate performance and cycle stability still need to be further improved. Therefore, finding a suitable negative electrode material has become an important research direction for sodium ion batteries.
[0004] The elemental substances (Si, Ge, Sn, P, Sb, Bi, and S, Se, etc.) or their alloys of the IV, V, and VI main groups can form binary and multi-element alloys with Li / Na. Due to their multiple electron exchange, they provide high theoretical specific capacity and relatively safe lithium / sodium insertion potential, and have attracted widespread attention. However, Na x M y (M = Si, Ge, Sn, P, Sb, Bi, S, Se) is often accompanied by a huge volume expansion, and the newly exposed active material surface continuously forms a SEI film during the cycle process, causing the SEI film to be rough and uneven in thickness, resulting in serious capacity decay. For example, metallic antimony has a high specific capacity (660 mAh g -1 ), good electrical conductivity (2.56×10 6 Sm -1), lower polarization voltage, low price, environmental friendly, etc. become a kind of excellent performance negative electrode material. However, the metal antimony in the antimony-based negative electrode material will expand about 300% in volume during the battery cycle process, which leads to the pulverization of active material and the detachment from the current collector or the direct contact of positive and negative electrode materials, and the metal antimony is prone to aggregation, which aggravates the consequences of expansion, leading to the pulverization of antimony electrode and the insufficient contact with electrolyte, and the newly formed antimony surface will lead to the formation of new SEI film, further leading to the loss of capacity, which greatly affects the performance of the battery. Therefore, in recent years, the research on antimony negative electrode material mainly focuses on how to improve the electronic conductivity of antimony-based material, relieve the volume expansion during the cycle process, mainly including nanocrystallization, morphology control, surface coating, composite material design, etc. SUMMARY
[0005] The present application aims at how to relieve the volume expansion problem of antimony negative electrode material, and provides a preparation method of antimony-doped graphite phase carbon nitride composite material, taking g-C3N4 as a precursor carbon source, Sb2O3 providing doped element metal antimony, and hot tartaric acid solution as a dissolving agent and a binder, the three are uniformly mixed, and then carbonized to obtain the antimony-doped graphite phase carbon nitride composite material.
[0006] To achieve the above object, the present application adopts the following technical scheme:
[0007] In the first aspect, the present application provides a preparation method of antimony-doped graphite phase carbon nitride composite material, comprising the following steps:
[0008] 1) Sb2O3 powder is added into hot tartaric acid to prepare a solution;
[0009] 2) g-C3N4 powder is added into the solution of step 1) and stirred to mix uniformly, and then dried into yellow block solid;
[0010] 3) the yellow block solid is placed in a tube furnace, carbonized at 600 DEG C to 800 DEG C for 1 to 6 hours in an inert gas environment, to obtain the antimony-doped graphite phase carbon nitride composite material.
[0011] In the above technical scheme, the mass ratio of g-C3N4 powder and Sb2O3 powder is 4 to 16:1. The larger the mass ratio, the more carbon in unit mass in the final negative electrode material, the better the cycle stability of the battery, and the capacity is relatively reduced. The smaller the mass ratio, the more metal antimony in unit mass of the synthesized negative electrode material, the capacity is improved, and the cycle stability is reduced. In this range, the cycle stability and capacity of the battery are relatively good.
[0012] In the above technical scheme, the temperature of the hot tartaric acid is 80 to 120 DEG C.
[0013] In the technical solution, the drying temperature in step 2) is 60-180 DEG C.
[0014] In the technical solution, the drying temperature in step 2) is 75 DEG C. The solid is dried at 75 DEG C. to make the block solid as regular as possible, reduce the gap between antimony tartrate and g-C3N4, and make the capacity and stability of the synthesized composite material optimal.
[0015] In the technical solution, the carbonization temperature in step 3) is 650-750 DEG C, preferably 700 DEG C.
[0016] The simple medium and high temperature firing process is adopted, g-C3N4 is used as a precursor carbon source, Sb2O3 provides a doped element metal antimony, and a hot tartaric acid solution is used as a dissolving agent and a binder, so that the three are organically and uniformly mixed, carbonized, and the antimony-doped graphite phase carbon nitride composite material is obtained. The g-C3N4 is a two-dimensional layered material, which is connected together through the weak van der Waals force interaction between layers, and is easy to insert the doped particles. The raw materials are easy to obtain, environmentally friendly, clean and pollution-free, and no gas polluting the environment is generated.
[0017] In the second aspect, the application provides application of the antimony-doped graphite phase carbon nitride composite material prepared by the preparation method in a lithium / sodium ion battery negative electrode material.
[0018] The lithium / sodium ion battery negative electrode material prepared by the application has good conductivity and high reversible capacity due to the existence of the metal antimony, and the carbon skeleton with the grid layered structure solves the problems of material pulverization and sharp decrease of battery stability caused by the easy agglomeration and volume expansion of the metal antimony.
[0019] In the third aspect, the application provides application of the antimony-doped graphite phase carbon nitride composite material prepared by the preparation method in a lithium / sodium ion battery, and the lithium / sodium ion battery comprises a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, wherein the negative electrode sheet comprises the antimony-doped graphite phase carbon nitride composite material.
[0020] Compared with the prior art, the application has the following beneficial effects:
[0021] The precursor carbon source g-C3N4 of the application is a two-dimensional layered material, which is connected together through the weak van der Waals force interaction between layers, and is easy to insert the doped particles. The composite material obtained by the method has excellent rate performance and stable performance cycle when applied in the lithium / sodium ion battery, and the material has very high commercial value.
[0022] The method is simple in process, and the raw materials are easy to obtain, environmentally friendly, clean and pollution-free, and no gas polluting the environment is generated. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 XRD pattern of g-C3N4 prepared for Example 3.
[0024] Figure 2 SEM photo of g-C3N4 prepared for Example 3.
[0025] Figure 3 SEM photo of graphite phase carbon nitride material fired at 700℃ for 2h for Comparative Example 2.
[0026] Figure 4 SEM overall photo and partial photo of antimony doped graphite phase carbon nitride composite material fired at 700℃ for Example 3.
[0027] Figure 5 Rate capability graph of sodium ion battery with the composite material of Examples 1-3 as negative electrode material.
[0028] Figure 6 Rate capability graph of lithium ion battery with the composite material of Examples 1-3 as negative electrode material.
[0029] Figure 7 Cycle performance of lithium / sodium ion battery with the composite material prepared for Example 3 as negative electrode material. DETAILED DESCRIPTION
[0030] The following examples are used to illustrate the present application, but are not used to limit the protection scope of the present application. If not specifically indicated, the technical means used in the examples are the conventional means known to those skilled in the art. The test methods in the following examples are the conventional methods, if not specifically indicated.
[0031] Example 1
[0032] The preparation method of the antimony doped graphite phase carbon nitride composite material in this example specifically includes the following steps:
[0033] 1) Put 20g of melamine into a ceramic crucible, and then put it into a muffle furnace to rise to 550℃ at a temperature rising speed of 5℃ / min for 2h, to obtain yellow block-shaped g-C3N4.
[0034] 2) Respectively take 4g of g-C3N4 solid and 1g of Sb2O3 powder according to the mass ratio of 4:1, for standby.
[0035] 3) Grind the g-C3N4 solid in a mortar for 1h, so that the yellow particles are as fine as flour without obvious block-shaped solid.
[0036] 4) Sb2O3 powder was poured into a small beaker, 5 mL of ultrapure water was added and heated and stirred with a magnet, forming a white mixed suspension, then poured into 25 mL of hot tartaric acid (100℃) at 500 g / L, heated and stirred until the solution was clear and transparent.
[0037] 5) g-C3N4 powder was poured into the Sb2O3 mixed aqueous solution, heated and stirred at 60℃ until it became viscous, then poured into a small porcelain boat, and heated at 60℃ until it completely solidified, obtaining a yellow block-shaped solid;
[0038] 6) The yellow block-shaped solid was placed in a tube furnace, heated to 700℃ at a rate of 5℃ / min under a nitrogen environment and kept for 4h, and naturally cooled to obtain a Sb-doped graphite phase carbon nitride composite material.
[0039] Example 2
[0040] 1) 20g of melamine was placed in a ceramic crucible, then placed in a muffle furnace and heated to 550℃ at a rate of 5℃ / min and kept for 2h, obtaining a yellow block-shaped g-C3N4.
[0041] 2) 6g of g-C3N4 solid and 1g of Sb2O3 powder were weighed according to the mass ratio of 6:1, respectively, for standby.
[0042] 3) The g-C3N4 solid was ground in a mortar for 1h, making the yellow particles as fine as flour without obvious block-shaped solid.
[0043] 4) Sb2O3 powder was poured into a small beaker, 5 mL of ultrapure water was added and heated and stirred with a magnet, forming a white mixed suspension, then poured into 25 mL of hot tartaric acid (100℃) at 500 g / L, heated and stirred until the solution was clear and transparent.
[0044] 5) g-C3N4 powder was poured into the Sb2O3 mixed aqueous solution, heated and stirred at 75℃ until it became viscous, then poured into a small porcelain boat, and heated at 75℃ until it completely solidified, obtaining a yellow block-shaped solid;
[0045] 6) The yellow block-shaped solid was placed in a tube furnace, heated to 700℃ at a rate of 5℃ / min under a nitrogen environment and kept for 4h, and naturally cooled to obtain a Sb-doped graphite phase carbon nitride composite material.
[0046] Example 3
[0047] The preparation method of the Sb-doped graphite phase carbon nitride composite material of the present embodiment specifically comprises the following steps:
[0048] 1) Take 20 g of melamine and put it into a ceramic crucible, then put it into a muffle furnace and heat it to 550°C at a rate of 5°C / min and keep it at this temperature for 2 h to obtain yellow block-shaped g-C3N4.
[0049] 2) Take 4.5 g of g-C3N4 solid and 0.5 g of Sb2O3 powder in a mass ratio of 9:1, respectively, and prepare them for use.
[0050] 3) Grind the g-C3N4 solid in a mortar for 1 h to make the yellow particles as fine as flour without obvious block-shaped solids.
[0051] 4) Pour the Sb2O3 powder into a small beaker, add 5 mL of ultrapure water and continuously heat and stir with a magnet to form a white mixed suspension, then pour it into 15 mL of hot tartaric acid (100°C) at a concentration of 500 g / L, and heat and stir until the solution is clear and transparent.
[0052] 5) Pour the g-C3N4 powder into the Sb2O3 mixed aqueous solution, continuously heat and stir at 100°C until it becomes viscous, then pour it into a small porcelain boat, and heat it to complete solidification at 100°C to obtain yellow block-shaped solids.
[0053] 6) Put the yellow block-shaped solids into a tube furnace, heat them to 700°C at a rate of 5°C / min under a nitrogen atmosphere and keep them at this temperature for 4 h, and then naturally cool them to obtain antimony-doped graphite-phase carbon nitride composite materials.
[0054] Example 4
[0055] The preparation method of the antimony-doped graphite-phase carbon nitride composite material of this embodiment specifically includes the following steps:
[0056] 1) Take 20 g of melamine and put it into a ceramic crucible, then put it into a muffle furnace and heat it to 550°C at a rate of 5°C / min and keep it at this temperature for 2 h to obtain yellow block-shaped g-C3N4.
[0057] 2) Take 4 g of g-C3N4 solid and 0.25 g of Sb2O3 powder in a mass ratio of 16:1, respectively, and prepare them for use.
[0058] 3) Grind the g-C3N4 solid in a mortar for 1 h to make the yellow particles as fine as flour without obvious block-shaped solids.
[0059] 4) Pour the Sb2O3 powder into a small beaker, add 5 mL of ultrapure water and continuously heat and stir with a magnet to form a white mixed suspension, then pour it into 10 mL of hot tartaric acid (100°C) at a concentration of 500 g / L, and heat and stir until the solution is clear and transparent.
[0060] 5) Pour the g-C3N4 powder into the mixed aqueous solution of Sb203, and continuously heat and stir at 120℃ until it becomes viscous, then pour it into a small porcelain boat, and heat at 120℃ until it completely solidifies to obtain a yellow block solid;
[0061] 6) Put the yellow block solid into a tube furnace, and heat to 700℃ at a heating rate of 5℃ / min under a nitrogen environment, and keep the temperature for 4h, and naturally cool to obtain the antimony-doped graphite phase carbon nitride composite material.
[0062] Comparative Example 1
[0063] This example is basically the same as Example 3, except that in step 6), the heating rate is 5℃ / min to 500℃ and the temperature is kept for 4h.
[0064] Comparative Example 2
[0065] The preparation method of the graphite phase carbon nitride negative electrode material is as follows:
[0066] 1) Put 20g of melamine into a ceramic crucible, and then put it into a muffle furnace to heat to 550℃ at a heating rate of 5℃ / min and keep the temperature for 2h to obtain a yellow block of g-C3N4.
[0067] 2) Put the yellow block solid into a tube furnace, and heat to 700℃ at a heating rate of 5℃ / min under a nitrogen environment, and keep the temperature for 4h, and naturally cool to obtain the graphite phase carbon nitride negative electrode material.
[0068] Figure 1 The XRD pattern of g-C3N4 prepared in Example 3 is shown, and this peak corresponds to the characteristic diffraction peak of the (002) crystal plane of g-C3N4, which is caused by the graphite layer-like stacking of π-conjugated planes, proving the layered structure of g-C3N4.
[0069] Figure 2 The SEM photo of g-C3N4 prepared in Example 3 is shown, which shows the micro-laminated structure of g-C3N4, with an interlayer spacing of hundreds of nanometers, providing conditions for the embedding of metallic antimony into the carbon skeleton.
[0070] Figure 3 The SEM photo of the graphite phase carbon nitride material prepared in Comparative Example 2 and burned at 700℃ for 2h is shown, which shows the network structure of the carbon skeleton, and no metallic antimony is embedded therein.
[0071] Figure 4 The SEM overall photo and partial photo of the antimony-doped graphite phase carbon nitride composite material burned at 700℃ in Example 3 are shown, the left photo shows the unique micro-disordered structure of the material, and the white particles in the right photo are metallic antimony, clearly showing the microstructure of the embedding of metallic antimony into the carbon skeleton.
[0072] The Sb-doped graphite phase carbon nitride composite material obtained in Examples 1-3, Comparative Examples 1-2, conductive carbon black and the binder sodium alginate were ground at a mass ratio of 7:1:2 for 1 h to prepare a slurry, the slurry was stirred uniformly and then coated on an aluminum foil, which was then placed in a drying oven and dried at 80°C under vacuum for 24 hours. The dried aluminum foil was cut into a circular negative electrode sheet of appropriate size, which was then assembled into a circular button cell with a specification of CR2032 in an argon-filled glove box for electrical property testing.
[0073] In an argon-filled glove box, lithium and sodium pieces, a separator (glass fiber separator), an electrolyte (1 mol / L sodium perchlorate, solvent: volume ratio of ethylene carbonate and diethyl carbonate 1:1 and 8% fluoroethylene carbonate), a material negative electrode sheet, a positive and negative electrode cell shell, a gasket, a spring and a button cell pressing machine were prepared. First, place the negative electrode cell shell upwards, place the lithium and sodium pieces, place the separator, add the electrolyte dropwise, place the material negative electrode sheet, place the gasket, place the spring, cover the positive electrode cell shell, seal the battery with the button cell pressing machine, and the assembly is complete and can be tested.
[0074] Figure 5 The rate performance graph of the sodium ion battery with the composite material of Examples 1-3 as the negative electrode material, from the graph, it can be seen that as the proportion of Sb2O3 powder required for the reaction decreases, the specific capacity of the battery decreases, and the rate performance of the materials of different proportions is very good, proving that the material has good rate performance for the storage of sodium ions.
[0075] Figure 6 The rate performance graph of the lithium ion battery with the composite material of Examples 1-3 as the negative electrode material, from the graph, it can be seen that as the proportion of Sb2O3 powder required for the reaction decreases, the specific capacity of the battery decreases, and the rate performance of the materials of different proportions is very good, proving that the material has good rate performance for the storage of lithium ions.
[0076] Figure 7 The cycle performance graph of the lithium / sodium ion half-battery with the composite material of Example 3 as the negative electrode material at a current of 1 A g -1 -1 -1 -1 -1
[0077] The above-described embodiments are merely preferred embodiments of the present application, merely used to explain the present application, and are not intended to limit the scope of the present application. For those skilled in the art, other embodiments can be easily obtained by substitution or change based on the technical content disclosed in the present specification. Therefore, any changes and improvements made on the principles of the present application shall be included in the scope of the present application.
Claims
1. A method for preparing an antimony-doped graphitic carbon nitride composite material, characterized in that, Includes the following steps: 1) Prepare a solution by adding Sb2O3 powder to hot tartaric acid; 2) Add g-C3N4 powder to the solution in step 1), stir and mix evenly, then dry into a yellow block solid; 3) Place the yellow blocky solid into a tube furnace and carbonize it at 600℃~800℃ for 1~6h in an inert gas environment to obtain antimony-doped graphite phase carbon nitride composite material.
2. The preparation method according to claim 1, characterized in that, The mass ratio of g-C3N4 powder to Sb2O3 powder is 4~16:
1.
3. The preparation method according to claim 1, characterized in that, The temperature of the hot tartaric acid is 80~120℃.
4. The preparation method according to claim 1, characterized in that, The drying temperature described in step 2) is 60℃~180℃.
5. The preparation method according to claim 1, characterized in that, The drying temperature described in step 2) is 75°C.
6. The preparation method according to claim 1, characterized in that, The carbonization temperature mentioned in step 3) is 650℃~750℃.
7. The application of the antimony-doped graphite-phase carbon nitride composite material prepared by the preparation method according to any one of claims 1 to 6 in the anode material of lithium / sodium-ion batteries.
8. The application of the antimony-doped graphite-phase carbon nitride composite material prepared by the preparation method according to any one of claims 1 to 6 in lithium / sodium-ion batteries.